Incandescent lamp.



C. E. CAMPBELL.

INGANDEBOBHT LAMP. Ammon-10111111.31 un. 1a. mio.

988,308. Patented 111511411911.

INCANDESCEN'r LAMP.

Specification of Letters Patent.

Hannns E CAMPBELL, or LYNN, MAssiici-iusnrtrs,` AssIGNuoB. To VAcuUMGLAss c ,OMPANL or LYNN. MASSACHUSETTS, A CORPORATION .oFMAssAcHusE'rrsln l 'Patented Apr.' 4, 1911.

Application filed April 18,' 1910.` Seriil No. 556,137.

To all whom fit may concern:`

Be it ltno'wirth'at I. CxmnLi-:s E. CAMP- BELL, a citizen of the lvnited States, residling at Lynn, 1u the county ot Essex and State ofMassachusetts. have invented certain new and useful Improvements in lncandescent Lamps; and l. do hereb \Y declare thefollowing to be a full. clear, and exact description of the4 invention, such as will enable others skilled in the art to which it appertains tovmake and use the same.

-V vent ion The present invention relates to an improvement in incandescent lamps.

The object of the invention is to produce `an unproved construction of tungsten hlament incandescent lamps.

To thls end.the invention consists m the incandescent lamp hereinafter described and I claimed.

20. preferred form of the invention.

The accompanyingdrawingl illustrates the :sists of a piece platinum wire having its end 6 penetrating the `glass bulb, being sccured therein by having the glass melted Vabout it. The inner end 7 of the filament braces one leg of the filament. If desiredf Support is provided with a loop which emthe portion of the filament support inside of the thickness ofthe glass of the bulb may i- .be made of copper or other metal welded or 40 otherwise securely attached to the platinum -portionof-the support.

Heretofore it has been proposed, and to a limited extent practiced, to provide to the filament support at the end of' a bulb by having` a projection of glass extendinward into the bulb and in fixing in such inward A:so

projection of'glass apiece of metal wire .having a loop which encircles the lamp filament. This form of' lamp in operation causes the deposit of a very considerable vquantity of the metal upon the inner surface' of. the bullo owing` to the temperature to which' the metal wire 'encircling the filament is subjected. lith the construction of the present invention, however, the filament sup.-

port extends into a thin port-ion of thc'bnlb so that the heat which the filamentfsupport receives from the filament is readily conducted to the surface of the bulb and there radiated away. Thus the filament-support 1s supported in such a manner that it radiates the heat which is imparted to itv by the filament. It will be observed thatthe loop portion of the filament-snpport approaches the filament in a direction at right angles to the latter so that movements of the filament in the support are not impeded in any way. This mode of support also contributes to secure the conduction of the heat from the support away from the fila1nent-support 'ine` end thereof as readily as possible.

An importantfeature of this invention 'resides in its adaptability to the manufacture of tungsten filament lamps .from old carbon filament lamps. Thus, a worn out carbon filament lamp may be opened by removing the closing tip. Through this opening the old filament may be removed, the leading-in wires may be bent to the proper form to receive and to have attached ther to. the ends of thetnngsten filament by providingthem at their ends with little open sided hooks which will hold the paste; The filament support ma v be conveniently sealed into the Igflassfat Vthe edge of this opening,

4then' the filamentmay be introduced through this opening passing one leg of the filament through theloop in the end thereof and extending theyfilament ends up to and attaching them to the ends of the leading-in wires.

fThe int'nbation of the pumping tube is next performed when the lamp is ready" for exiaustion. In the manufacture of new lamps the flament'support would be inserted at a as to need support at its end.

Having` thus described the inventlon, what -is claimed isr- 1. An inca-ndescent-filament vacuum-lamp comprising a filament and a glass bulb .and a platinum filament support penetrating a thin portion of the glass bulb encircling the filament, substantially as described.

2.. An incandescent-filament lVacuum-lamp comprising 4a filament and a glass bulb and a vlatnurn filament supportpenetrating a thm portion of the glass bulb and having.;` an end encircling the filament and leadvling away from the lament in directions at right angles to the filament so as hereby to conduct the heat imparted to it y ment to the outer surface of the bulb so as thereby to prevent the Ilament from heating the filament support to ,such temperature to cause it to produce a metallic deposit uponthe inside of the bulb, substantially as described.

the filament away from the fila-- 3. An incandescent-filament vacuumvlamp comprising a filament and a glass bulb, and a lament support of heat conducting material having one end formed with a loop embracing the lament and having theJ other end penetrating a thin portion of the glass 2o bulb so that the outer end of the lament- 

